The present invention relates generally to electronics cooling, and more particularly to system for natural convection cooling of an integrated circuit die.
Like other electronic components, microprocessors are typically rated to a safe operating temperature above which component degradation and damage are more likely to occur. Microprocessors continue to decrease in physical size while increasing in process capacity and corresponding heat output. As a result, microprocessor cooling systems must be made capable of dissipating larger amounts of heat from smaller contact points. A variety of systems exist to provide cooling for microprocessors, including forced convention cooling. Forced convection cooling relies on relatively cool airflow driven by a fan or bled from a pressurized air source, and accordingly requires power and fault monitoring.
Modern microprocessors are often mounted on ball grid array (BGA) chip carriers that fan out connections from the microprocessor to provide contact points to a printed wiring board via solder balls. These solder balls expand and contract from thermal cycling during normal operation, thereby causing changes in the height of the BGA chip carrier and the microprocessor die. Microprocessor dies are typically relatively fragile. If constrained by a hard attached heat exchanger that directly loads the die, the resulting stress can fracture the die during thermal cycling.